sql columns to rows

PremiseWhen this article discusses only SQL Server queries,For non-composite statistics, where the statistics for each field contain only the data distribution of theHow to estimate the number of rows based on statistical information when combining

The table has three columns: stunamem and subjectscore. table data includes: zhang San Language 0 Li Si Language 4 Wang Er English 90 Zhang San mathematics 333 requirements query results below student language English mathematics Zhang San 00333 Li

In the development of the report, many times will encounter row and column conversion operations, the developer for the SQL level row and column conversion operation has been not very understanding, today just time to make some simple summary. Here

Original: T-SQL rows merged into columns and columns split rowsThe source of this article: http://www.cnblogs.com/wy123/p/6910468.htmlI feel the recent SQL has not written less, suddenly a little rusty, for use is not too frequent some operations,

The table has three columns: stunamem and subject score.Table data includes:Zhang San Language 0Li Si Language 4Wang 'er English 90Zhang San, mathematics 333The query results are as follows:Chinese and English mathematics for studentsZhang San 0 0 33

The source of this article: http://www.cnblogs.com/wy123/p/6910468.htmlI feel the recent SQL has not written less, suddenly a little rusty, for use is not too frequent some operations, time is easy to live.One column of multiple rows merged into one

1: Three ways to build a tableBuilding a table will only create a table in the library and display it in the log, and there will be no output.1.1: Define columns yourself to create an empty tableColumn-specification = column-define +

Database structureAnd I want to make the same person's different grades into this person. displayed on different columns of this line, this time divided into 2 shows:The first shows----"Multiple rows to one column" (the merged data is on the same

How to use transform to convert rows and columns; In Oracle, to convert rows and columns, DECODE and CASE statements are commonly used. For simple row and column conversion, DECODE and CASE statements can still cope with it. In scenarios where the

This article mainly introduces the pandas data processing basis to filter the specified row or the specified column of the relevant information, the need for friends can refer to the following The main two data structures of Pandas are: series